The bill would require employers to prove that any discrepancies between male and female pay are job-related and not based in discrimination, considering a census report revealed that women typically earn 77 cents for every dollar their male counterparts earn for the same position.

Marcie Kinzel, Brown's Washington communications director, noted that the junior senator from Massachusetts voted against the bill in 2010's lame-duck session and that he is not changing his position.

“Senator Brown believes strongly in fair pay, and that employers who discriminate against women should be prosecuted aggressively," Kinzel said in a statement. "However, on the bill before the Senate, Senator Brown believes it will put more burdens on small businesses and could lead to job losses at a time when our economy can least afford it.”

Although Brown didn't personally wade into the debate on Monday, Senate Republicans have said the Democratic push at this legislation, which mirrors the failed 2010 bill, is another attempt to make it look like Republicans are voting against women's rights.

His office noted that he supports and would have voted for the Lilly Ledbetter Fair Pay Act of 2009 which extended the statute of limitations for women looking to seek compensation for long-term pay discrepancies based on gender.

The vote is expected to take place on Tuesday sometime after 2 p.m.

Elizabeth Warren, Brown's rival in the Massachusetts Senate race, said the senator's expected vote sends a bad message to women in the Bay State.

“With his vote, Scott Brown is telling the women of Massachusetts he thinks it’s okay that they continue to earn less than men with the same education doing the same work," Warren said. "His vote is costing Massachusetts families hard earned dollars that they can’t afford to lose in these tough times."